Video camera lens

Abstract

The invention provides a video lens, and relates to the technical field of optical lenses. The video camera lens comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are sequentially arranged from the object side to the image side along the optical axis. The focal power of the first lens is negative, the focal power of the second lens is negative, the focal power of the third lens is positive, the focal power of the fourth lens is positive, the focal power of the fifth lens is positive, the focal power of the sixth lens is negative, the focal power of the seventh lens is negative, and the focal power of the eighth lens is positive. The embodiment of the invention provides a video lens, so as to realize a video lens system with small volume, low distortion and high resolution.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to a video lens. Background Art

[0002] With the continuous upgrading and development of Internet technology, fixed-focus lenses are widely used in video conferencing, online teaching, online video shooting and other fields, and have received more and more attention from the public. Therefore, the requirements for their image quality are getting higher and higher. It is difficult for video conferencing lenses on the market today to meet high standards in terms of both size and distortion, and it is difficult to meet the requirements of use in various occasions. The high-end market's demand for high-resolution, small-volume, low-distortion lenses is still increasing. Therefore, designing a small-volume, low-distortion, and high-resolution video lens has become a market development trend. Summary of the invention

[0003] The embodiment of the present invention provides a video lens to realize a video lens system with small volume, low distortion and high resolution.

[0004] An embodiment of the present invention provides a video lens, comprising a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence from the object side to the image side along an optical axis;

[0005] The optical focal power of the first lens is negative, the optical focal power of the second lens is negative, the optical focal power of the third lens is positive, the optical focal power of the fourth lens is positive, the optical focal power of the fifth lens is positive, the optical focal power of the sixth lens is negative, the optical focal power of the seventh lens is negative, and the optical focal power of the eighth lens is positive.

[0006] Optionally, the first lens is a glass spherical lens, the second lens is a plastic aspherical lens, the third lens is a glass spherical lens, the fourth lens is a plastic aspherical lens, the fifth lens is a glass spherical lens, the sixth lens is a glass spherical lens, the seventh lens is a plastic aspherical lens, and the eighth lens is a plastic aspherical lens.

[0007] Optionally, a surface of the first lens facing the object side is a convex surface, and a surface of the first lens facing the image side is a concave surface;

[0008] A surface of the second lens facing the object side is concave, and a surface of the second lens facing the image side is convex;

[0009] The side of the third lens facing the object side is convex, and the side of the third lens facing the image side is convex;

[0010] The surface of the fourth lens facing the object side is convex, and the surface of the fourth lens facing the image side is concave;

[0011] The surface of the fifth lens facing the object side is convex, and the surface of the fifth lens facing the image side is convex;

[0012] The surface of the sixth lens facing the object side is concave, and the surface of the sixth lens facing the image side is convex;

[0013] The surface of the seventh lens facing the object side is concave, and the surface of the seventh lens facing the image side is convex;

[0014] The surface of the eighth lens facing the object side is convex, and the surface of the eighth lens facing the image side is concave.

[0015] Optionally, the optical power of the first lens is The optical power of the second lens is The focal power of the third lens is The optical power of the fourth lens is The optical power of the seventh lens is The optical power of the eighth lens is The combined optical power of the seventh lens and the eighth lens is The optical power of the video lens is Satisfies at least one of the following relations:

[0016]

[0017] Optionally, the full aperture of the first lens is D1, and the total length of the video lens is TTL, satisfying the relationship: 0.325≤D1 / TTL≤0.355.

[0018] Optionally, the refractive index of the first lens is ND1, the Abbe number of the first lens is VD1, 1.380≤ND1≤1.645, 56.50≤VD1≤96.50;

[0019] and / or,

[0020] The object side surface of the first lens has a curvature radius of S1, the image side surface of the first lens has a curvature radius of S2, and 1.65≤(S1+S2) / (S1-S2)≤2.85.

[0021] Optionally, the fifth lens and the sixth lens form a doublet lens with positive optical power.

[0022] Optionally, the refractive index of the fifth lens is ND5, the Abbe number of the fifth lens is VD5, 1.35≤ND5≤1.65, 65.50≤VD5≤96.50;

[0023] and / or,

[0024] The optical power of the doublet lens is The optical power of the video lens is

[0025] Optionally, the center thickness of the second lens on the optical axis is d2, the center thickness of the fourth lens on the optical axis is d4, the center thickness of the seventh lens on the optical axis is d7, the center thickness of the eighth lens on the optical axis is d8, and the total optical length of the video lens is TTL, satisfying: 0.215≤(d2+d4+d7+d8) / TTL≤0.265.

[0026] Optionally, the total optical length of the video lens is TTL, the half image height of the video lens is H, and 4.285≤TTL / H≤4.325 is satisfied;

[0027] and / or,

[0028] A distance from a center of the image side surface of the eighth lens to a center of the image plane is BFL, which satisfies: 0.195≤BFL / TTL≤0.215.

[0029] The video lens provided in the embodiment of the present invention includes 8 lenses, and the optical power of the first lens to the eighth lens is: negative, negative, positive, positive, positive, negative, negative, positive. The number of lenses is reasonable, the structure is simple and compact, and the optical power and position of each lens are reasonable, achieving small size, low distortion and high resolution. The aperture number FNO of the video lens is 1.90, the field of view angle is not less than 70°, the imaging target surface can match a 1 / 2.7-inch chip, the total optical length is not more than 15mm, and the absolute value of optical distortion is not more than 2.5%, meeting the requirements of ultra-high-definition imaging. It can be used in video conferencing, online teaching, network video shooting and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a video camera provided in Embodiment 1 of the present invention;

[0031] Figure 2 A spherical aberration curve diagram provided in Example 1 of the present invention;

[0032] Figure 3 A light fan diagram provided by the first embodiment of the present invention;

[0033] Figure 4 A schematic diagram of field curvature provided in Embodiment 1 of the present invention;

[0034] Figure 5 A schematic diagram of distortion provided in Embodiment 1 of the present invention;

[0035] Figure 6A schematic diagram of the structure of a video camera provided in Embodiment 2 of the present invention;

[0036] Figure 7 A spherical aberration curve diagram provided in Embodiment 2 of the present invention;

[0037] Figure 8 A light fan diagram provided by the second embodiment of the present invention;

[0038] Fig. 9 A schematic diagram of field curvature provided in Embodiment 2 of the present invention;

[0039] Fig.10 A schematic diagram of distortion provided in Embodiment 2 of the present invention;

[0040] Fig.11 A schematic diagram of the structure of a video camera provided in Embodiment 3 of the present invention;

[0041] Fig.12 A spherical aberration curve diagram provided by Embodiment 3 of the present invention;

[0042] Fig.13 A light fan diagram provided by Embodiment 3 of the present invention;

[0043] Fig.14 A schematic diagram of field curvature provided in Embodiment 3 of the present invention;

[0044] Fig.15 A schematic diagram of distortion provided in Embodiment 3 of the present invention;

[0045] Fig.16 A schematic diagram of the structure of a video camera provided in a fourth embodiment of the present invention;

[0046] Fig.17 A spherical aberration curve diagram provided by the fourth embodiment of the present invention;

[0047] Fig.18 A light fan diagram provided by the fourth embodiment of the present invention;

[0048] Fig.19 A schematic diagram of field curvature provided in Embodiment 4 of the present invention;

[0049] Fig. 20 A schematic diagram of distortion provided in Embodiment 4 of the present invention;

[0050] Fig.21 A schematic diagram of the structure of a video camera provided in Embodiment 5 of the present invention;

[0051] Fig. 22 A spherical aberration curve diagram provided by Embodiment 5 of the present invention;

[0052] Fig.23A light fan diagram provided by Embodiment 5 of the present invention;

[0053] Fig.24 A schematic diagram of field curvature provided in Embodiment 5 of the present invention;

[0054] Fig.25 A distortion diagram provided in Embodiment 5 of the present invention;

[0055] Fig.26 A schematic diagram of the structure of a video camera provided in Embodiment 6 of the present invention;

[0056] Fig. 27 A spherical aberration curve diagram provided in Example 6 of the present invention;

[0057] Fig.28 A light fan diagram provided by Embodiment 6 of the present invention;

[0058] Fig.29 A schematic diagram of field curvature provided in Embodiment 6 of the present invention;

[0059] Fig.30 This is a distortion diagram provided in Example 6 of the present invention. DETAILED DESCRIPTION

[0060] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0061] Embodiment 1

[0062] Figure 1 This is a schematic diagram of the structure of a video lens provided in the first embodiment of the present invention, referring to Figure 1 The video lens comprises a first lens 1, a second lens 2, an aperture STO, a third lens 3, a fourth lens 4, a fifth lens 5, a sixth lens 6, a seventh lens 7 and an eighth lens 8 which are arranged in sequence from the object side to the image side along the optical axis. The optical power of the first lens 1 is negative, the optical power of the second lens 2 is negative, the optical power of the third lens 3 is positive, the optical power of the fourth lens 4 is positive, the optical power of the fifth lens 5 is positive, the optical power of the sixth lens 6 is negative, the optical power of the seventh lens 7 is negative, and the optical power of the eighth lens 8 is positive.

[0063] The aperture STO is located between the second lens 2 and the third lens 3, which is beneficial to reducing the value of the aperture number FNO of the video lens.

[0064] The video lens provided in the embodiment of the present invention includes 8 lenses, and the optical powers of the first lens 1 to the eighth lens 8 are: negative, negative, positive, positive, positive, negative, negative, positive. The number of lenses is reasonable, the structure is simple and compact, and the optical power and position of each lens are reasonable, achieving small size, low distortion and high resolution. The aperture number FNO of the video lens is 1.90, the field of view angle is not less than 70°, the imaging target surface can match a 1 / 2.7-inch chip, the total optical length is not more than 15mm, and the absolute value of optical distortion is not more than 2.5%, meeting the requirements of ultra-high-definition imaging. It can be used in video conferencing, online teaching, network video shooting and other fields.

[0065] Optionally, refer to Figure 1 , the first lens 1 is a glass spherical lens, the second lens 2 is a plastic aspherical lens, the third lens 3 is a glass spherical lens, the fourth lens 4 is a plastic aspherical lens, the fifth lens 5 is a glass spherical lens, the sixth lens 6 is a glass spherical lens, the seventh lens 7 is a plastic aspherical lens, and the eighth lens 8 is a plastic aspherical lens. The video lens provided in the embodiment of the present invention adopts 4G4P, that is, it adopts 4 glass spherical lenses and 4 plastic aspherical lenses, and realizes small size, low distortion and high resolution by reasonably matching the optical power, position and material of each lens.

[0066] Optionally, refer to Figure 1 , the first lens 1 has a convex surface facing the object side, and the first lens 1 has a concave surface facing the image side, and the first lens 1 is a convex-concave lens. The second lens 2 has a concave surface facing the object side, and the second lens 2 has a convex surface facing the image side, and the second lens 2 is a concave-convex lens. The third lens 3 has a convex surface facing the object side, and the third lens 3 has a convex surface facing the image side, and the third lens 3 is a biconvex lens. The fourth lens 4 has a convex surface facing the object side, and the fourth lens 4 has a concave surface facing the image side, and the fourth lens 4 is a convex-concave lens. The fifth lens 5 has a convex surface facing the object side, and the fifth lens 5 has a convex surface facing the image side, and the fifth lens 5 is a biconvex lens. The sixth lens 6 has a concave surface facing the object side, and the sixth lens 6 has a convex surface facing the image side, and the sixth lens 6 is a concave-convex lens. The seventh lens 7 has a concave surface facing the object side, and the seventh lens 7 has a convex surface facing the image side, and the seventh lens 7 is a concave-convex lens. The side of the eighth lens 8 facing the object side is convex, and the side of the eighth lens 8 facing the image side is concave, and the eighth lens 8 is a convex-concave lens. By reasonably matching the optical power, position, shape and material of each lens, a small volume, low distortion and high resolution are achieved.

[0067] Optionally, refer to Figure 1 , the focal length of the first lens 1 is The optical power of the second lens 2 is The optical power of the third lens 3 is The optical power of the fourth lens 4 is The optical power of the seventh lens 7 is The optical power of the eighth lens 8 is The combined optical power of the seventh lens 7 and the eighth lens 8 is The optical power of the video lens is Satisfies at least one of the following relations:

[0068] Exemplarily, the first lens 1 is designed as a meniscus-shaped negative lens with a convex surface facing the object side, and the optical power of the first lens 1 is The optical power of the video lens is satisfy In this way, light with a large field of view can enter the video lens as much as possible, which is beneficial to increasing the field of view angle of the video lens.

[0069] Optionally, refer to Figure 1 The full aperture of the first lens 1 is D1, and the total length of the video lens is TTL, which satisfies the relationship: 0.325≤D1 / TTL≤0.355. This is beneficial to reducing the volume of the video lens and realizing the miniaturization of the video lens.

[0070] Optionally, refer to Figure 1 , the refractive index of the first lens 1 is ND1, the Abbe number of the first lens 1 is VD1, 1.380≤ND1≤1.645, 56.50≤VD1≤96.50. The Abbe number of the first lens 1 is reasonably allocated to improve the chromatic aberration of the video lens.

[0071] Optionally, refer to Figure 1 , the radius of curvature of the object side of the first lens 1 is S1, the radius of curvature of the image side of the first lens 1 is S2, and 1.65≤(S1+S2) / (S1-S2)≤2.85. Among them, the object side refers to the surface of the lens (such as the first lens 1) facing the object side, that is, the front surface. The image side refers to the surface of the lens (such as the first lens 1) facing the image side, that is, the back surface. Setting 1.65≤(S1+S2) / (S1-S2)≤2.85 can help to converge light from different fields of view and improve imaging brightness.

[0072] Exemplarily, the second lens 2 is designed as a concave-convex negative lens, and the optical power of the second lens 2 is The optical power of the video lens is satisfy: On the one hand, it can effectively control the trend of light, reduce the field curvature and spherical aberration of the video lens, and improve the image quality of the optical video lens; on the other hand, by designing the second lens 2 to be a concave-convex aspheric lens symmetrical to the first lens 1, the purpose of low distortion design can be achieved.

[0073] For example, the third lens 3 is designed as a biconvex positive lens. The third lens 3 is located after the aperture STO, which can effectively control the light to smoothly enter the rear of the video lens, reduce the spherical aberration of the video lens, and improve the imaging quality of the video lens. The optical power of the third lens 3 is The optical power of the video lens is satisfy This helps to balance the light aberration in front of the aperture STO.

[0074] Exemplarily, the fourth lens element 4 is designed as a meniscus-shaped negative lens with a convex surface facing the object side, and the optical power of the fourth lens element 4 is The optical power of the video lens is This can help control the direction of light, reduce the angle of light deflection, reduce the system sensitivity of the video lens, and help improve production yield.

[0075] Optionally, refer to Figure 1 , the fifth lens 5 and the sixth lens 6 form a doublet lens with positive power.

[0076] Furthermore, the focal power of the doublet lens is The optical power of the video lens is The refractive index of the fifth lens 5 is ND5, and the Abbe number of the fifth lens 5 is VD5, 1.35≤ND5≤1.65, 65.50≤VD5≤96.50. By setting the double-cemented lens material and reasonably setting the optical power of the double-cemented lens, it is beneficial to balance the chromatic aberration of the video lens and improve the imaging quality of the video lens; at the same time, it can also smoothly transmit light, reduce the tolerance sensitivity of the video lens, and improve the assembly yield of the video lens.

[0077] Exemplarily, the seventh lens 7 is designed as a concave-convex negative lens, and the eighth lens 8 is designed as a convex-concave positive lens. The seventh lens 7 and the eighth lens 8 are symmetrically arranged, which can effectively control the direction of light, raise the direction of light, meet the image size requirements and improve the illumination. The optical power of the seventh lens 7 is The optical power of the eighth lens 8 is The optical power of the video lens is satisfy: This is beneficial to controlling aberrations, reducing tolerance sensitivity, and improving image quality. The combined focal power of the seventh lens 7 and the eighth lens 8 is The optical power of the video lens is satisfy: This can effectively correct the optical distortion, making the absolute value of the optical distortion less than or equal to 2.5%, while improving the optical imaging performance of the optical video lens.

[0078] Exemplarily, a filter 9 is provided on the side of the eighth lens 8 facing the image plane IMA, and the light enters through the filter 9. Considering that a CMOS photosensitive chip will be used when applied to lens imaging, the filter 9 has a certain protective effect on the photosensitive chip, and also filters a part of the light to reduce stray light, so that the image is bright and sharp while having good color reproduction.

[0079] Optionally, refer to Figure 1 , the center thickness of the second lens 2 on the optical axis is d2, the center thickness of the fourth lens 4 on the optical axis is d4, the center thickness of the seventh lens 7 on the optical axis is d7, the center thickness of the eighth lens 8 on the optical axis is d8, and the total optical length of the video lens is TTL, which satisfies: 0.215≤(d2+d4+d7+d8) / TTL≤0.265. This can make each lens have better processability, which is beneficial to reducing the sensitivity of the video lens; at the same time, it is beneficial to reduce the air space between the lenses, thereby reducing the total optical length of the video lens, so that the total optical length of the video lens TTL≤15mm.

[0080] Optionally, refer to Figure 1 , the total optical length of the video lens is TTL, the half image height of the video lens is H, and 4.285≤TTL / H≤4.325 is satisfied. Under the condition of a certain image height, the reasonable setting of the total optical length of the video lens is conducive to the miniaturization of the video lens.

[0081] Furthermore, the distance from the center of the image side surface of the eighth lens 8 to the center of the image plane IMA is BFL, and the total optical length of the video lens is TTL, which satisfies: 0.195≤BFL / TTL≤0.215. This can improve the assembly yield of the video lens, and also help to reserve space for the installation of optical components, facilitating the assembly of the video lens.

[0082] Table 1 A design value of the video lens in Example 1

[0083]

[0084] Table 1 shows a design value of the video lens in the first embodiment, and its specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 1 can be Figure 1As shown in . A lens generally includes two surfaces, each of which is a refractive surface. The surface numbers in Table 1 are numbered according to the order of the surfaces of each lens. Among them, surface number 1 represents the front surface of the first lens 1 (i.e., the object side), surface number 2 represents the back surface of the first lens 1 (i.e., the image side), and so on, which will not be repeated here. "STO" means aperture. The units of radius of curvature, thickness and semi-aperture are all mm. The radius of curvature represents the degree of curvature of the corresponding lens surface. A positive value represents that the surface is bent toward the image side, and a negative value represents that the surface is bent toward the object side. "INF" means that the surface is a plane and the radius of curvature is infinite. Thickness represents the central axial distance from the current surface to the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. The space represents that the current position is air and the refractive index is 1. The Abbe number represents the dispersion characteristics of the material between the current surface and the next surface to light. The space represents that the current position is air. The value in the semi-aperture column represents the half-height of the light corresponding to the current surface. k is a conic section constant.

[0085] Table 2 A design value of the aspheric coefficient of the lens in the video lens in Example 1

[0086]

[0087] Table 2 shows a design value of the aspheric coefficient of the lens in the video lens in Example 1. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 2 can be Figure 1 The meaning of the column "surface number" in Table 2 is consistent with that of the column "surface number" in Table 1. "E" in each embodiment of the present invention represents an index with base 10.

[0088] Optionally, the surface of the aspheric lens satisfies the formula:

[0089]

[0090] Among them, z is the axial vector height of the aspheric surface in the Z direction; r is the height of the aspheric surface; c is the curvature of the fitted sphere, which is the inverse of the radius of curvature; k is the fitted cone coefficient; A, B, C, D, E, and F are the coefficients of the 4th, 6th, 8th, 10th, 12th, and 14th order terms of the aspheric polynomial.

[0091] For example, in the first embodiment, the focal length f is 5.045 mm, the F# (ie, the aperture number FNO) is 1.90, the field of view angle DFOV=70°, the total optical length TTL: 14.89 mm; and the optical distortion: -2.0%.

[0092] For example, in the first embodiment, D1 / TTL=0.349; ND1=1.517; VD1=64.212; (S1+S2) / (S1-S2)=2.213; ND5=1.497; VD5=81.61; (d2+d4+d7+d8) / TTL=0.241; TTL / H=4.302; BFL / TTL=0.205.

[0093] Figure 2 A spherical aberration curve diagram provided in Example 1 of the present invention, referring to Figure 2 , the vertical direction represents the normalization of the aperture, 0 represents the optical axis, the vertical vertex represents the maximum pupil radius; the horizontal direction represents the offset relative to the ideal focus, in millimeters (mm). The different linear curves in the figure represent different wavelengths of system imaging, which are represented by Figure 2 It can be seen that the axial aberrations at different wavelengths are all controlled within the range of (-0.05mm, +0.05mm), indicating that the spherical aberration of the video lens at each wavelength is well controlled and can meet the needs of wide spectrum applications.

[0094] Figure 3 A light fan diagram is provided in the first embodiment of the present invention, referring to Figure 3 The light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays are focused on the same point on the image plane. The corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Figure 3 It can be seen that each wavelength of the video lens in each field of view is well aligned with the horizontal axis, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the video lens is also well corrected, thereby ensuring that the video lens can achieve high-resolution imaging requirements.

[0095] Figure 4 This is a schematic diagram of field curvature provided in the first embodiment of the present invention, referring to Figure 4 , the horizontal coordinate represents the magnitude of field curvature, in mm; the vertical coordinate represents the normalized image height, without unit; T represents meridian, S represents sagittal; Figure 4 It can be seen that the video lens provided in this embodiment is effectively controlled in terms of field curvature from light with a wavelength of 436nm to light with a wavelength of 650nm, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small.

[0096] Figure 5 This is a schematic diagram of distortion provided in the first embodiment of the present invention, referring to Figure 5 , the horizontal coordinate represents the size of the distortion, the unit is %; the vertical coordinate represents the normalized image height, no unit; Figure 5 It can be seen that the distortion of the lens of this embodiment is relatively small.

[0097] Embodiment 2

[0098] The similarities with the above-mentioned embodiment are not repeated here.

[0099] Table 2 A design value of the video lens in Example 2

[0100]

[0101] Table 3 shows a design value of the video lens in the second embodiment, and its specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 2 can be Figure 6 as shown in .

[0102] Table 4 A design value of the aspheric coefficient of the lens in the video lens in Example 2

[0103]

[0104] Table 4 shows a design value of the aspheric coefficient of the lens in the video lens in the second embodiment. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 4 can be Figure 6 as shown in .

[0105] For example, in the second embodiment, the focal length f is 4.972 mm, the F# (ie, the aperture number FNO) is 1.90, the field of view angle DFOV=70°, the total optical length TTL: 14.90 mm; and the optical distortion: -1.84%.

[0106] For example, in the second embodiment, D1 / TTL=0.348; ND1=1.593; VD1=68.346; (S1+S2) / (S1-S2)=2.409; ND5=1.497; VD5=81.61; (d2+d4+d7+d8) / TTL=0.245; TTL / H=4.319; BFL / TTL=0.208.

[0107] Embodiment 3

[0108] The similarities with the above-mentioned embodiment are not repeated here.

[0109] Table 5: Design values ​​of the video lens in Example 3

[0110]

[0111] Table 5 shows a design value of the video lens in the third embodiment, and its specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 5 can be Fig.11 as shown in .

[0112] Table 6 A design value of the aspheric coefficient of the lens in the video lens in Example 3

[0113]

[0114] Table 6 shows a design value of the aspheric coefficient of the lens in the video lens in the third embodiment. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 6 can be Fig.11 as shown in .

[0115] For example, in the third embodiment, the focal length f is 4.95 mm, the F# (ie, the aperture number FNO) is 1.90, the field of view angle DFOV=70°, the total optical length TTL: 14.90 mm; and the optical distortion: 1.99%.

[0116] For example, in Embodiment 3, D1 / TTL=0.352; ND1=1.438; VD1=94.577; (S1+S2) / (S1-S2)=1.751; ND5=1.497; VD5=81.61; (d2+d4+d7+d8) / TTL=0.250; TTL / H=4.319; BFL / TTL=0.208.

[0117] Embodiment 4

[0118] The similarities with the above-mentioned embodiment are not repeated here.

[0119] Table 7 A design value of the video lens in the fourth embodiment

[0120]

[0121] Table 7 shows a design value of the video lens in the fourth embodiment, and its specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 7 can be Fig.16 as shown in .

[0122] Table 8 A design value of the aspheric coefficient of the lens in the video lens in Example 4

[0123]

[0124] Table 8 shows a design value of the aspheric coefficient of the lens in the video lens in the fourth embodiment. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 8 can be Fig.16 as shown in .

[0125] For example, in the fourth embodiment, the focal length f is 4.89 mm, the F# (ie, the aperture number FNO) is 1.90, the field of view angle DFOV=70°, the total optical length TTL: 14.90 mm; and the optical distortion: -1.31%.

[0126] For example, in the fourth embodiment, D1 / TTL=0.343; ND1=1.593; VD1=68.346; (S1+S2) / (S1-S2)=2.076; ND5=1.497; VD5=81.61; (d2+d4+d7+d8) / TTL=0.236; TTL / H=4.319; BFL / TTL=0.208.

[0127] Embodiment 5

[0128] The similarities with the above-mentioned embodiment are not repeated here.

[0129] Table 9: Design values ​​of the video lens in Example 5

[0130]

[0131] Table 9 shows a design value of the video lens in the fifth embodiment, and its specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 9 can be Fig.21 as shown in .

[0132] Table 10 A design value of the aspheric coefficient of the lens in the video lens in Example 5

[0133]

[0134] Table 10 shows a design value of the aspheric coefficient of the lens in the video lens in Example 5. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 10 can be Fig.21 as shown in .

[0135] For example, in Example 5, the focal length f is 4.95 mm, the F# (ie, the aperture number FNO) is 1.90, the field of view angle DFOV=70°, the total optical length TTL: 14.90 mm; and the optical distortion: -1.61%.

[0136] For example, in Embodiment 5, D1 / TTL=0.344; ND1=1.593; VD1=68.346; (S1+S2) / (S1-S2)=2.384; ND5=1.437;VD5=95.10; (d2+d4+d7+d8) / TTL=0.245; TTL / H=4.319; BFL / TTL=0.208.

[0137] Embodiment 6

[0138] The similarities with the above-mentioned embodiment are not repeated here.

[0139] Table 11: Design values ​​of the video lens in Example 6

[0140]

[0141] Table 11 shows a design value of the video lens in the sixth embodiment, and its specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 11 can be Fig.26 as shown in .

[0142] Table 12 A design value of the aspheric coefficient of the lens in the video lens in Example 6

[0143]

[0144] Table 12 shows a design value of the aspheric coefficient of the lens in the video lens in Example 6. The specific value can be adjusted according to product requirements and is not a limitation of the embodiment of the present invention. The video lens shown in Table 12 can be Fig.26 as shown in .

[0145] For example, in Example 6, the focal length f is 4.98 mm, the F# (ie, the aperture number FNO) is 1.90, the field of view angle DFOV=70°, the total optical length TTL: 14.90 mm; and the optical distortion: -2.20%.

[0146] For example, in Example 6, D1 / TTL=0.343; ND1=1.593; VD1=68.346; (S1+S2) / (S1-S2)=2.615; ND5=1.593;VD5=68.62; (d2+d4+d7+d8) / TTL=0.235; TTL / H=4.320; BFL / TTL=0.210.

[0147] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A video camera, characterized in that: comprising a first lens, a second lens, an aperture, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens arranged in sequence from the object side to the image side along the optical axis; The optical focal power of the first lens is negative, the optical focal power of the second lens is negative, the optical focal power of the third lens is positive, the optical focal power of the fourth lens is positive, the optical focal power of the fifth lens is positive, the optical focal power of the sixth lens is negative, the optical focal power of the seventh lens is negative, and the optical focal power of the eighth lens is positive.

2. The video lens according to claim 1, characterized in that: The first lens is a glass spherical lens, the second lens is a plastic aspherical lens, the third lens is a glass spherical lens, the fourth lens is a plastic aspherical lens, the fifth lens is a glass spherical lens, the sixth lens is a glass spherical lens, the seventh lens is a plastic aspherical lens, and the eighth lens is a plastic aspherical lens.

3. The video camera according to claim 1, characterized in that: The first lens has a convex surface facing the object side and a concave surface facing the image side; A surface of the second lens facing the object side is concave, and a surface of the second lens facing the image side is convex; The side of the third lens facing the object side is convex, and the side of the third lens facing the image side is convex; The surface of the fourth lens facing the object side is convex, and the surface of the fourth lens facing the image side is concave; The surface of the fifth lens facing the object side is convex, and the surface of the fifth lens facing the image side is convex; The surface of the sixth lens facing the object side is concave, and the surface of the sixth lens facing the image side is convex; The surface of the seventh lens facing the object side is concave, and the surface of the seventh lens facing the image side is convex; The surface of the eighth lens facing the object side is convex, and the surface of the eighth lens facing the image side is concave.

4. The video camera according to claim 1, wherein: The focal power of the first lens is φ1, the focal power of the second lens is φ2, the focal power of the third lens is φ3, the focal power of the fourth lens is φ4, the focal power of the seventh lens is φ7, the focal power of the eighth lens is φ8, the combined focal power of the seventh lens and the eighth lens is φ78, and the focal power of the video lens is φ, which satisfies at least one of the following relationships: -0.75≤φ1 / φ≤-0.55; -0.205≤φ2 / φ≤-0.010; 0.75≤φ3 / φ≤1.05; 0.01≤φ4 / φ≤0.15; -0.305≤φ7 / φ≤-0.05; 0.25≤φ8 / φ≤0.365; 0.025≤φ78 / φ≤0.

185.

5. The video camera according to claim 1, characterized in that: The full aperture of the first lens is D1, and the total length of the video lens is TTL, which satisfies the relationship: 0.325≤D1 / TTL≤0.

355.

6. The video camera according to claim 1, wherein: The refractive index of the first lens is ND1, the Abbe number of the first lens is VD1, 1.380≤ND1≤1.645, 56.50≤VD1≤96.50; and / or, The object side surface of the first lens has a curvature radius of S1, the image side surface of the first lens has a curvature radius of S2, and 1.65≤(S1+S2) / (S1-S2)≤2.

85.

7. The video camera according to claim 1, wherein: The fifth lens and the sixth lens form a doublet lens with positive refractive power.

8. The video camera according to claim 7, characterized in that: The refractive index of the fifth lens is ND5, and the Abbe number of the fifth lens is VD5, 1.35≤ND5≤1.65, 65.50≤VD5≤96.50; and / or, The optical power of the double-cemented lens is φ56, and the optical power of the video lens is φ, 0.245≤φ56 / φ≤0.

45.

9. The video camera according to claim 1, wherein: The center thickness of the second lens on the optical axis is d2, the center thickness of the fourth lens on the optical axis is d4, the center thickness of the seventh lens on the optical axis is d7, the center thickness of the eighth lens on the optical axis is d8, and the total optical length of the video lens is TTL, satisfying: 0.215≤(d2+d4+d7+d8) / TTL≤0.

265.

10. The video camera according to claim 1, wherein: The total optical length of the video lens is TTL, the half image height of the video lens is H, and 4.285≤TTL / H≤4.325 is satisfied; and / or, A distance from a center of the image side surface of the eighth lens to a center of the image plane is BFL, which satisfies: 0.195≤BFL / TTL≤0.215.

Images